I really am impressed by the 306s I picked up a few months back. I have been shifting around my workspace at home, and so have still not done what I need to do to calm down reflections where they are now, but I still have had an easy time working with them. I need to get that in order and would like to investigate options for DSP correction, which I need to learn more about. I actually bought them before discovering this site, and the world of more/better measurements, so it was really great to see that the choice I made based on a much more haphazard afternoon of research actually does measure well. Much more confidence in what I think I'm hearing, haha.
Is what you describe the same as the Bob Katz method for setting levels that he describes in his mastering book?
I too keep my levels in those same ranges, and there the JBLs don't begin to distort, though past a certain point I can hear them get muddied. I'm sure a sub would make a difference there though.
I have worked a fair amount on Focal Twin6 Bes and had great luck. This is in a well designed studio w/ a sub, and the room helps immensely. I have other points of comparison, but with lots of variables that make it hard to directly compare.. I have spent a decent amount of time on other presumably comparable monitors but consistently had nasty surprises in my mixes. Hopefully some of that's just improvement with time, but the measurements support that the Focals should be trustworthy!
And..... NS-10s get used a lot as well. Obviously they are not flat.. Has anyone done a spinorama of one of those?? I would really love to see what is going on there. I was a skeptic for a long time, I basically just thought they sounded awful, but came to see what they are used for, or at least one way to use them. Not that I don't still think they sound kind of awful! I know I've happened across a bit of analysis of why engineers find them useful, something about console bounce was part of it perhaps, but as I recall it was a bit old.. I've assumed it's just a combination of low distortion midrange in the most important bands, maybe lack of resonances created by any attempt to play bass, and the bandwidth limiting being useful so as to focus on the most crucial frequencies for clarity in a mix without being distracted by bass or sparkly extended highs, a filter.
May I ask you, what your hearing, listening and production experience is?
Most beginners make the mistake, that they do not learn properly, how certain instruments in different songs (should) sound.
What does that mean?
You could start with kick and bass and you need to learn to hear (and how it sounds in
your room), the different kinds of kicks (and how the bassline & 1st & 2nd harmonics are placed in relation to the kick). But not in the amateurish way, but you need to hear, how a 50 with a 100 Hz bump with a carved out 80 Hz range kick sounds like (MJs Billy Jean comes to mind), or how a house kick with the peak at 58 and loud 80 and 100 does sound, and how house kicks with a 50 or 65 peak sound, or how a trance kick with a soft 80-100 pressure zone sounds like.
Without having the ability to work in a professional environment without professional producer mentoring, you could get a decent pair of headphones and a good analyzer with very high resolution in the low end. And then start to listen to a lot of your personal reference tracks.
But the problem is, without monitors, its very hard to achieve good sounding mixes.
So my suggestion would be, to also use monitors, that do not exacerbate bass problems by simply not producing lots of bass. Auratones. They have the additional benefit, that their midrange in the near field is simply reference. IME a Neumann speaker does not have any advantages to them in the crucial midrange.
IME it is also by far the best suited speaker to hear ambience, reverb and delays and the stereo imaging on them. With enough distance to walls, the Auratones at arm length allow to hear the side-channel like I have never heard on any other speaker.
And there are other benefits from their midrange focused (reference) monitoring: the midrange focus does not only allow to easily if the levels (even of of bass instruments) are correct, but they allow to hear easily, if a kick or the bassline is too weak on smaller speakers and needs additional harmonics.